Comprehensive Description

Description

“Zoroaster actinocles, sp. n.

Rays 5. R=161 mm., r=11 mm., R=14.6r; breadth of ray at base, 13 mm. Rays slender, evenly tapered to the extremity, which is capped by a relatively large terminal plate; disk elevated at centre; carinal ridge rather prominent. Resembling a slender-rayed Z. fulgens, but differing in having the plates of the second, third, and fourth actinolateral series smaller, the fourth series being rudimentary; in having slenderer superomarginal spines (which are decidedly slen­derer than the carinal spines), fleshier spinelets, relatively larger carinal plates, never but one actinolateral spine to a plate; in having a decidedly larger terminal plate, and a large pedicellaria on the second (from furrow) adambulacral spine. The papular pores are small; there are five regular longitudinal series, with the beginning of a sixth at base of ray, on either side of the carinal plates—namely, two dorso­lateral, one intermarginal, 2+1 incomplete actinolateral series. Papulae solitary and small. Carinate or prominent adambulacral plates with a transverse series of five spines, the first deep in furrow, the second with a pedicellaria about 1.5 mm. long attached to its base.